AC Hacking a Figidaire 5000 BTU

I have been working on it today. The Bilge blower is a bit, OK more than a bit loud and I wanted to slow it down some. No luck finding a rheostat able to handle the 4.5 A on the spur of the moment so I settled for a couple of wire wound resistors which may slow it down too much, or not, all it has to do is overcome the restrictions and help the air move along. I also relocated the control wires to come out of the top/cold line rather than the return to facilitate use/installation of the blower.
 
I am including this in the original post but wanted to elaborate on a couple of items.
the Tearjerkers Crossroads of America Gathering was the real life test of the system with temperatures in the upper 80's high humidity and no breeze. Saturday night it did not cool off much and we left it running all night. Come morning it was covered with condensation and you can see that.
The bilge blower is now three speed, full no resistance, and with the use of resistors in the negative line, medium and slow. I found that the slow was sufficient to overcome the restrictions in the air movement enough to prevent freezing. My next step will be trying a PMW to regulate speed. The resistors get HOT and while I sandwiched them between a couple of pieces of aluminum to help dissipate that I hate wasting that much energy and I can see instance where a variable speed would be a good addition.

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Very nice. I have been following this one closely, and plan to utilize many of your techniques.

I recently scored a 2 year old GE 6100BTU unit that has the digital control panel on it. I will be extending the control unit into my camper by extending the 7 wires that connect it. The control unit will mount in the forward wall of the camper.

I have had trouble locating marine deck plates locally, but discovered that a plumbing drain for showers from the local hardware store, combined with a rubber hose coupler will actually work perfectly for me.
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Remove the drain grate on top, and the rubber coupler slides VERY snugly inside that. The large nut on the backside gets removed entirely, and you mount 2 or three screws through the flange into the trailer.

In my case, my AC will be perma-mounted to the tongue of the trailer, and the duct-work for the cold supply lines will be 2 1/2" flexible exhaust pipe. Cover it all with a box and call it good.

I look forward to your changes with the PWM and will stay tuned.
 
I can't tell from the pics, but you may want to add feet to the unit so it doesn't sit in a puddle of water.

Another thing you may want to look into is to drill a couple drain holes on the bottom. I have the same unit in my tear and the bottom acts like a pan holding some condensate. The drain is on the side of the lip which allows some water to stay in the pan. When I drive off, that little bit of water sloshes out. Not a big deal, but a little annoying.
 
Finding deck plates, I ordered mine on line after comparing those available. The cover goes on and locks with a 1/4 turn into an O ring seal.
 
Very cool!! I'm an AC tech of 16 years and I've never seen such a creative way to cool a small space! Bravo!

I'm going to dis-assemble a window unit and and create a mini "split" system. I'm thinking I'll have the condenser exhast out the bottom of the trailer and duct in the evaporator using 1/8 inch ply . All under the counterspace in the galley. FYI - they do have digital voltage t-stats is you wanted to go that route in the future.
 
Do you think the freezing up could be eliminated by allowing the unit to suck a little outside air through a smaller hole in the custom fab housing?
 
That wouldn't help the problem of icing up I don't believe. Icing up is usually caused by improper air flow caused by a dirty evaporator or filter . There are other conditions that cause it but most if the time it's caused by improper airflow. A good way to prevent ice buildup is to install a "freeze stat" . This monitors evaporator temp and shuts compressor down when temps get too low. It's real easy to do and will solve the icing problem .
 
What I finally ended up with was a PMW to control the speed of the bilge blower. I had started out using a couple of heavy duty resistors which get HOT. I purchased a 30A variable PMW and put it in a Radio Shack project box. This works perfectly and the result is a package that is easily transportable and very very quiet. The reason for the bilge blower is that you are imposing restrictions in the airflow and need to help things along.
You could perhaps use a hole to help, but one of my goals was to dehumidify as much as possible. I have seen those that use only a single hose from the cold side, but I wanted a closed circuit to accommodate an air filter/purifier. I also wanted a unit that could stand being outside and basically weather proof.
The window shakers I have encountered work by slinging the condensed water helping to cool the condenser. In this case I elected to not drill a drain hole as much because I did not want the possibility of a pool of water. I do however prop up the evaporator side so the water ends up being slung. And yes you do have to empty before transporting.
 
Genius idea. My thoughts on this subject were to just set the A/C unit, as it came from the factory, on a chair outside the door and run a duct into the partially open door. Bug netting would need to be covering the rest of the door opening. With an inline switch for the 110v reachable from inside, this would allow warm air to go out the top vent and cool fresh air to be pumped in from the A/C.
Your application is SUPER!
Thanks
Sj
 
I think in my case, instead of holes in the wall for the vent, I'd just make a frame to fit the bottom of the window, like the unit might normally do, but size it for the 14" window width and then just close my window down on it. Stick the unit underneath and have it blow forward, under the trailer. I have an outlet underneath outside that has a switch inside. I was thinking for lights outside but an air unit would suit me too. :)
How small do they make window units?
I have been considering dismantling one of those peltier electric coolers, and maybe I could do it with 4 peltier plates and a couple pc muffin fans. 12vdc system. maybe even solar and/or wind powered.
 
PC, we tried a 2500 BTU Pet Cool on MM #1 and found it could not keep up with heat gain. Compass Rose and MM#1 have a higher interior volume than most teardrops about 400 cubic feet, but have 1.5" foam insulation. One reason I went with the deck plates is to keep the hoses to the AC reasonably short and the other is that I have an Eberspacher heater in a case that uses the same hoses (good to 400 degrees) to heat the trailer.
Considering the difficulties I don't know that using peltier electric coolers would be any where near enough to do what you want at best they keep one of the coolers at 40 degrees below ambient temperatures and that is a very small volume of space, they also fail if they get wet... http://www.tetech.com/FAQ-Technical-Information.html
"Large thermoelectric systems in the kilo-watt range have been built for specialized applications such as cooling within submarines and railroad cars or cooling process baths in specialized areas such as in semiconductor manufacturing. In cases where thermoelectric coolers are used for such large applications there generally has been a good reason why a vapor compressor system has not been used (for example, vibration needs to be minimized or precision temperature control is required). In which case, the extra cost and higher power consumption of the thermoelectric cooler can be justified."

Again let me stress this system is virtually silent the trailer isolated from the AC unit by the hoses, and dehumidifies very well. Any one hose system will keep you cool but likely a bit soggy.
 
well, it's not about the noise, or the size of the unit, it's about the voltage to run it. I wanted to cool at 12v dc. (someone here said that it was impossible, so they leave me with no choice but to do it. ;-) Now I agree that it must stay dry or you'll short out the peltier(s). Any cooling process must condense moisture. May have to put a layer of duct tape with caulk rim in there, for the cooling phase. One thing I am going to attempt that no one else here is doing yet, since I have the "house like" trailer, is to put in a water heating system in the roof rafters, inside the roof, under the shingles, under the particle board, in the ceiling. What this does is two fold, one, I get boiling hot water on summer days. (MAYBE luke warm in winter, but I doubt it. winter unit for next winter.) The other thing it does for me is to absorb a HUGE proportion of the radiant heat BEFORE it gets to my insulation, inbound. (I may go multi-layer for the foam sheets. I have 3.5 inches to work with as that is my roof joist depth, 2x4's (1.5's x 3.5's) For the winter I have been heating with a 200 watt hair dryer (forced air) and a 500w halogen work light (infrared heating.) 80F inside with 20F outside. So I'm pretty well insulated from the wind and cold. In the summer I am going to re-open the soffits/eaves (sp, under the roof edge) which I closed for the winter work, with foam. Too windy in the winter, but not nearly enough for the summer. So we'll see. Solar panel and/or windmill for 12v power. All I can say for sure is that I will have hot water in the summer. I don't know how small I can get away with for the hose, but it may end up pushing boiling. I may end up boiling all my water trying to keep the interior cool. (Hmmm, maybe a steam generator... LOL!) Maybe instead of a solar panel I'll go with a peltier panel on the roof. Should be 20F diff. between sides in the sun. It's a thought. I was saving the AC looking box on my tongue to be a battery box that looks like an AC unit... (maybe I'll end up with an AC unit that looks like a hedge...) :thinking:

Another thing I have seen is to have a tub of ice with coils of metal hose, then bring that to a fan and metal coils, to AC something. You'd melt the ice, but it might be a two bag a day cooling system. I could go "no 110" as long as I have the ice and the 12 volt source for the pump and the fans (muffin: computer 3W@12v dc)

@Shadow Catcher, you are right about one thing. I'm 93.35 cu ft, interior, or about 19 times the volume of a cooler. So even if I do get that many peltier plates together I still have to power them... hmmm. I hope it's a really windy day and I windmill a 100 amp alternator. LOL that would give me 5 amps per peltier, and 5 amps left for fans. Maybe at the beach... otherwise I better pray for shade, or full tarp.
 
Good info treeview. Draw back with half of those is that I live in Michigan and anywhere over 40% humidity and the California/swamp cooler idea is out. For the other half, it shows some good stuff. Good research points. Thanks Sensi. :)

Actually, I already have the electronic controller built for 4 zone ceiling/roof, outside air temp and two places inside air temp system. (I was experimenting with it a few years back on something else. Both heating and cooling. So like the truck unit, that part is built.)

According to the radiant system, I should put aluminum foil on the outer side of the insulation sheets, since they are not already there. I need to just make sure I have an air gap for breathing a bit, and that will be the hose area for the water heating. The blue cooler idea is kind-of what I was thinking for actual making things colder, but I'd have to dismantle it as, if the cooler is inside I have the heat exhaust inside with me fighting me, so I'd have to vent the hot air outside. Winter it would be like a heat pump and probably not so efficient to use the peltier. I'd rather go back to the "vegetable oil candle fueled, micro, rocket mass stove for the winter" idea.
 
When I was looking for information I worked with finding the calculations to make an informed decision as to exactly how much coolth I needed. The problem is that most of the calculations I found only address square foot, 'floor space' not cubic foot 'volume' which does not make a great deal of sense as not all rooms are 8' ceilings (our house has 9'). Nor do they allow for insulation, windows. This calculatior has it all!
http://www.consumerreports.org/cro/appl ... /index.htm
I figure there would be some built in inefficiency in using hoses that are not insulated etc. and also realized I had to figure we would be in southern climes where we would need more coolth.
The Peltier cooling blocks are from what I can see very inefficient in their power consumption. The most powerful peltier cooling chip I have heard of, generates about 374 btu's in per hour.
 
Something more like this, but on a MUCH larger scale.
http://www.instructables.com/id/Air-CoolerHeater/

Yeah, that page would be better off with latitude, sq feet of southern wall, wall thickness and insulation, sq ft of southern roof, thickness and insulation, then size of all remaining outer surfaces, thickness and insulation.

I need to go look up a "Pet Cool"
http://www.thermassure3.com/
says it cools with a compressor, not a peltier. 110v ac, max size recommended is 216 cu ft (6' x 6' x 6') and I'm 94 cu ft.
I'll do my water heater first and then see how much heat is left inside.
I'm considering 3-5 gallon storage containers underneath, forward of the axel, and pumped independently. I'll see how that goes with insulation to the max.
 
I contacted several of the thermoelevtric manufacturers and they all said the closest they have is thousands of dollars and still not capable of cooling a small camper.
 
Hey Jpageau

Check out the crazy stuff I tried so far starting with shadow catchers ideas


http://overthetopcargotrailer.blogspot.com/

I tried making a single hose LG into a duel hose unit ..... BUT not to my satisfaction

I have been thinking about ripping apart a window unit to make a mini split .... BUT how do you extend the thermostat ? attached to the evaporator ?
as far as i'm concerned it could just run wide open full power !!!

if i'm still not happy I have some 18k & 24k Chinese mini splits SEER 13 , that heat and cool if I get really desperate...
I stole them for only $850 including the copper pipes :D

MY all time FAV is the Fujitsu 12RLS SEER 26 - R410A , but the piece of :x :x all run 240 volts


PS ... Thanks again to Shadow Catcher for his first idea
 
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